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part 1: MH3000 / RoVa3D tools & setup

A while back I went in halfsies on an MH3000 KickStarter printer from ORD Solutions, just down the road in Cambridge, ON. As there’s still under 100 of these printers out there, it can be a bit hard to find information on how to get going with one. Here’s some tips from my first 100 hours of operation.

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Essential Tools

You absolutely need these tools, or you’ll be pulling your hair out in short order. Buy them while you’re waiting for your printer to ship. I keep all of these right by the printer.

Calipers, analogue or digital, with metric readout. I recommend: one, two. $20-$30. You’ll be using these all the time to measure all sorts of machine tolerances, printer parts, filament width, things you want to replicate with your printer, things you print out, etc.

Hobbyist long nose pliers. I recommend: one, two. $5-30. These are great for getting in underneath the print head and pulling off globs of melted filament, and keeping your fingers far away, safe and not burned. I use these all the time to deal with oozing PLA just prior to a print.

Hobbyist diagonal cutters, full or semi flush cut. Many options, here’s one. $5-30. I use these to cut filament, wires, strip wires (carefully), and sometimes stray printed filament off of a print in progress. You need this more often than you realize, and small cutters are easier to use than scissors or a larger pair.

Hobby knife with extra #11 blades. I recommend: one. These are useful to clean up printed items, but more importantly these help keep your nozzles clean if they drag through printed parts accdentially as you can scrape off the filament easily. You can also use the blades (carefully!!!) to lift parts from the print bed. If you do this, remove the blade from the knife and place the entire blade edge flat against the print bed at a low angle. Work the blade slowly under the part until it detaches. Do this at multiple points around the perimeter of the part.

Feeler gauges. I recommend: one, two. $10-25. You’ll need these to “gap” the space between the print bed and the nozzles, and to re-validate anytime you adjust the print carriage. The Lee Valley set here is superior because they’re 5 1/2″ long and focuses on thinner sizes, even though you’ll need to convert from imperial to metric. (Most sets at e.g. auto supply shops are only 2-3″ long.)

5″ (short) 10mm wrench. I recommend: one. This is required for adjusting the height of the print nozzles. I believe KS2 backers now get this included, but I might be wrong.

6″ adjustable wrench. I recommend: one, though mine is thinner. For tweaking all the various nuts on the printer without needing a full wrench set.

Some clean rags / washcloths

100% Acetone. $5-10. Available at any paint store.

Window cleaner in a spray bottle. $5. You’ll want this to apply Kapton tape to your print bed. Mine’s citrus based because it smells nicer than melted plastic. :)

Old / inactive / promotional credit card. I use an empty Tim Hortons gift card (they’re free!) You’ll use this to “squeegee” the tape.

Filament storage

One thing that I had to figure out for myself is that PLA and ABS both like to absorb moisture from the air. Have a drying solution figured out before you unseal the filament from the bags as they arrive. This means a resealable air-tight container with a dessicant large enough to hold the filament spools – the ORD spools are 10″ in diameter.

I assembled containers from buckets to keep my filament dry. The cost is about $25. You need:

If you leave your filament out for even just 24h, it can start to become water logged. You’ll know this happens when you are extruding and you see steam rising or hear a quiet “popping” sound, or for transulcent filament you see bubbles in the extruded filament. To fix this, you can put the spool in a 150-170F oven for 1-3h, and let thoroughly cool before use. Be careful to calibrate your oven before trying this!

Optional tools

I have all of these – you can get by without them if on a budget, but for best results I recommend them. Sorted in priority order:

Den-On 70-51-00 Cleaning Pin Set. $6. Picture here. This is an incredible tool, which is effectively 3 14cm long wires, of 0.8, 1.0 and 1.5 mm gauge, held together by a soft green rubber. You can use these to clear blockages in the hot ends while they’re still hot and push stuck filament out of the extruders.

9/32″ socket driver. $5. I use a screwdriver that takes various bits and a socket from a kit similar to this one. This is the exact size for the nuts underneath the print bed. With a screwdriver handle you can more easily give all 3 printer bed nuts the same amount of turn and raise the print bed evenly, or offset by 1/8 of a turn if you want to tilt it just slightly.

Zip and twist ties. I use quite a few of these for cable management.

12″ / 30cm metal ruler. $5-10. I have a cork-backed Westcott R590-12 that I probably bought for school years ago. For general measuring.

IR Thermometer. I recommend the Pro Exotics PE-2. $40 with free US shipping. This unit has an adjustable emissivity setting, which you can use to adjust for the different properties of materials you’re measuring.

12″ Starrett straight edge or rule. I recommend: one, two. $60. You can’t buy a better straight edge, as these are accurate to ±0.0002″ per foot. This plus feeler gauges will help you determine any warp, bump or cup in your printer bed. I find this a faster approach than mounting a dial indicator to the print carriage and measuring values all over the bed.

Dial indicator + optional metal base. I recommend: one. I used this prior to getting the Starrett straight edge for checking bed flatness. They’re still useful for checking out-of-round for various metal printer parts, but this is an advanced step that many of you won’t need. You can print a holder that mounts to the X carriage to measure flatness of the bed. I don’t recommend this approach anymore, as dial indicators are both more expensive and more fiddly than using a straight edge plus feeler gauges.

Setup

These videos and the text below them walk you through the most salient points. I picked up my printer from the factory, so I skipped the first 3 videos.

Setup tips and tricks

I had a hard time figuring out how to use the lint-free cloth to act as a filament wiper. First, save your twist ties as you unbundle cables. Cut the provided cloth into strips. After feeding filament into the extruder, below the short tube that’s below the extruder, wrap the cloth around and around the filament like you’re wrapping a sprained ankle. Use the twist tie to hold the cloth against the filament. I wrap the tie around 5 or 6 times, then leave about 3cm free for twisting together to apply sufficient friction. You want to tighten the twist tie enough so that, as the filament feeds, most of the cloth stays below the tubing.

When feeding the filament, note that the hole in the extruder is smaller than the hole in the mounting plate. As a result you may find the filament gets stuck in that lip. Don’t force it! I lost a huge piece of my thumbnail when my hand flew up into the extruder gear. You could probably epoxy/fill in the lip to have a smoother infill, but I’ve not tried this yet.

6 thoughts on “part 1: MH3000 / RoVa3D tools & setup”

These are great tips. Thanks for posting them. My printer is up and running but still in the tool chain pain part of the learning curve and hit my first nozzle jam. Nothing like bathing in unknowns to make you feel like a kid again.

Thank you Joan, It is a very helpful bunch of data, I am looking forward to your second part.
A question, shouldn’t there be a kind of protection for the rolls of filament when they are mounted on the printer? I was thinking of a plastic bag somehow enveloping the rolls with a small hole for the filament to come out and some silica inside the bag… does it make sense?

Hi Rafael. I understand your point, but unless you expect there to be a lot of debris in the area, the bags are probably overkill. I recommend keeping your printer on a shelf unit so that there is some protection above and below the printer. Since the filaments will only be mounted for a short time (during printing) and the wiper will keep the filament clean as it heads into the extruder, you should be fine without the bag. But if you do try a filament bag, let me know — and please share some pictures!

Your suggestion of using razorblades to pull the part up sent shivers down my spine, as I flashed back to every time I’ve sliced myself open with similar tactics. :)

I picked up a Cricut spatula tool, they’re designed for scrapbooking but the spatula is thin enough that I can get underneath just about any printed part. Looks like they don’t have them on Amazon anymore, but it’s pretty much identical to this one: